An
electric power distribution system is the final stage in the
delivery of
electric power; it carries electricity from the
transmission system to individual consumers. Distribution substations connect to the
transmission system and lower the transmission voltage to medium voltage ranging between 2
kV and 35 kV with the use of
transformers.
Primary distribution lines carry this medium voltage power to
distribution transformers located near the customer's premises. Distribution transformers again lower the voltage to the
utilization voltage of household appliances and typically feed several customers through
secondary distribution lines at this voltage. Commercial and residential customers are connected to the secondary distribution lines through
service drops. Customers demanding a much larger amount of
power may be connected directly to the primary distribution level or the
subtransmission level.